Comparing crushed recycled glass to silica sand for dual media filtration

Abstract

The objective of this project was to evaluate the performance of a pressure filter utilizing crushed glass as the filter media in a dual media anthracite–glass filter compared to a dual media anthracite–sand filter. In general, the particle removal capabilities of the crushed-glass filter were slightly poorer than those of a sand filter, as quantified in a field application in the community of Orangedale, Nova Scotia. It was found that the crushed glass used in this project had a higher angularity and slightly higher uniformity coefficient then the sand tested. After 6 months of use the crushed-glass filter was able to produce a filter effluent of 50–70 particles/mL (diameter >2 μμm), which is greater than the 25–50 particles/mL (diameter >2 μμm) that was produced by sand filter. Over the course of the 6-month study the dual media crushed-glass filter was able to achieve a 1.4-log removal, which was only slightly greater than the dual media silica sand filter that achieved a 1.6-log removal of particles with diameters >2 μμm. Key words: filtration, drinking water, recycled glass, sustainability, particle counting.